Browsing by Author "Fernando, I.V.S."
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Item Aphid Repellency of Croton lacciferus. L.(Sri Lanka Association for the Advancement of Science, 1986) Wimalaratne, P.D.C.; Wickramasinghe, L.K.G.; Fernando, I.V.S.; Wijeyaratne, M.J.S.Item Apomecyna saltator (F) (Coleoptera: Cerambycidae), A stem-borer of snake gourd(Sri Lanka Association for the Advancement of Science, 1991) Fernando, I.V.S.; Abhayawardena, T.A.Item Biology of Pyrilla perpusilla Walker (Homoptera:Lophopidae), A pest of Sugarcane in the Wet Zone of Sri Lanka.(Journal of Entomology, 2006) Ganehiarachchi G.A.S.M.; Fernando, I.V.S.Item Natural enemies of sugarcane Planthopper Pyrilla perpusilla Walker (Homoptera: Lophopidae)(Journal of the National Science Foundation of Sri Lanka, 2000) Ganehiarachchi G.A.S.M.; Fernando, I.V.S.Item Parachrysocharis javensis an effective egg parasitoid of Sugarcane Planthopper Pyrilla perpusilla Walke (Homoptera:Lophopidae) in the wet zone of Sri Lanka.(Vidyodaya Journal of Science, 2000) Ganehiarachchi G.A.S.M.; Fernando, I.V.S.Parachrysocharis javensis is an effective egg parasitoid of Pyrilla perpusilla in the west zone of Sri Lanka. This study was conducted through out a period of two years to determine the percentage parasitism of this parasitoid and factors affecting it. The percentage egg cluster parasitism was positively correlated with the number of egg clusters present in the field. It was also confirmed that percentage parasitism was negatively correlated with rainfall and humidity and positively correlated with daily minimum and maximum temperature.Item Partial age specific life table of Sugarcane planthopper Pyrilla perpusilla Walker (Homoptera: Lophopidae)(Journal of Entomology, 2007) Ganehiarachchi G.A.S.M.; Fernando, I.V.S.Neotephritis finalis (Loew) (Diptera: Tephritidae), and sunflower bud moth, Suleima helianthana (Riley) (Lepidoptera: Tortricidae) are major head-infesting insect pests of cultivated sunflower (Helianthus annuus L.). Planting date was evaluated as a cultural pest management strategy for control of N. finalisand S. helianthana in several production regions of North Dakota during 2009 and 2010. Results of the nine site-year study revealed that late planting date (early to mid-June) reduced damage ratings and percentage of damaged heads for N. finalis compared with early planting dates (mid- to late May). Visual observations of adult N. finalis found that the majority of flies were found in the early planted sunflower (78.2%) compared with the late planted sunflower (21.8%). Late planting date also reduced the percentage of S. helianthana damaged heads compared with early planting dates. Yield losses were reduced with late planting date when populations of N. finalis and S. helianthana were high enough to cause damage. Results of this study showed that delayed planting is an effective integrated pest management strategy that can reduce head damage caused by N. finalis and S. helianthana and mitigate yield losses.Item Population dynamics of the sugarcane Planthopper Pyrilla perpusilla Walker (Homoptera: Lophopidae) in the wet zone of Sri Lanka(Journal of Tropical Science, 2000) Ganehiarachchi G.A.S.M.; Fernando, I.V.S.In the wet zone of Sri Lanka, a field experiment was conducted to study the population dynamics of the sugar cane planthopper (Pyrilla perpusilla). The numbers of eggs, nymphs and adults were high in July, August and Oct. 1993, April and Sep. 1994, and Feb. and March 1995. Population size showed a negative correlation with rainfall and humidity and positive correlation with minimum temperature. A hymenopteran parasitoid (Parachrysocharis javensis) and 9 species of predators of the planthopper were recorded in the plot. The main factors responsible for the fluctuation of the planthopper population were the egg parasitoid, the predators and the amount of rainfall.Item Some aspects of the biology of Pteroma plagiophleps Hampson (Lepidoptera: Psychidae), A defoliator of Delonix regia (Boj) (Leguminosae: Caesalpiniaceae)(Sri Lanka Association for the Advancement of Science, 1991) Fernando, I.V.S.; Jayakody, D.S.Item Some aspects of the life histories of Ephestia cautella (Lepidoptera: Pyralidae) and Tribolium castaneum (Coleoptera: Tenebrionidae) infesting herbal tea and a method to control them using a lethal temperature that does not affect flavour(Sri Lanka Association for the Advancement of Science, 2005) Yapa, A.U.D.; Fernando, I.V.S.Item Trachys herilla Oben. (Coleoptera: Buprestidae), A leaf-miner of Okra(Sri Lanka Association for the Advancement of Science, 1991) Fernando, I.V.S.; Bandaranayake, D.R.